Abstract
Purpose. To determine the optimal geometry for keratoprostheses. Methods. A number of biopolymers were considered, among them, various plastics such as pMMA or pHEMA and various polysiloxanes. Their refractive index and dispersion were measured using an Abbe refractometer (Zeiss, Germany) and the values were incorporated in the framework of an eye model derived from the Gullstrand's eye model. Ray-tracing methods were used to determine the optimal parameters of the keratoprosthesis as a function of the eye parameters. The field of view was then calculated using paraxial approximations. Results. Flat designs, i.e. designs where the length of the keratoprosthesis is smaller than its diameter, are advisable because the field of view is enlarged and decentration problems are minimized. If the material used has a low refractive index, optical aberrations should be corrected with aspherical surfaces. Conclusions. New flexible biopolymers with a low refractive index such as polytrifluorosiloxane, are potential candidates for keratoprosthesis. They are mimicking the actual cornea, allowing a design as close as possible to the physiological conditions, while their flexibility may enable IOP measurements.
| Original language | English |
|---|---|
| Journal | Investigative Ophthalmology and Visual Science |
| Volume | 37 |
| Issue number | 3 |
| State | Published - Feb 15 1996 |
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ASJC Scopus subject areas
- Ophthalmology
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Optics of keratoprostheses. / Rol, P.; Parel, Jean-Marie A.
In: Investigative Ophthalmology and Visual Science, Vol. 37, No. 3, 15.02.1996.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Optics of keratoprostheses
AU - Rol, P.
AU - Parel, Jean-Marie A
PY - 1996/2/15
Y1 - 1996/2/15
N2 - Purpose. To determine the optimal geometry for keratoprostheses. Methods. A number of biopolymers were considered, among them, various plastics such as pMMA or pHEMA and various polysiloxanes. Their refractive index and dispersion were measured using an Abbe refractometer (Zeiss, Germany) and the values were incorporated in the framework of an eye model derived from the Gullstrand's eye model. Ray-tracing methods were used to determine the optimal parameters of the keratoprosthesis as a function of the eye parameters. The field of view was then calculated using paraxial approximations. Results. Flat designs, i.e. designs where the length of the keratoprosthesis is smaller than its diameter, are advisable because the field of view is enlarged and decentration problems are minimized. If the material used has a low refractive index, optical aberrations should be corrected with aspherical surfaces. Conclusions. New flexible biopolymers with a low refractive index such as polytrifluorosiloxane, are potential candidates for keratoprosthesis. They are mimicking the actual cornea, allowing a design as close as possible to the physiological conditions, while their flexibility may enable IOP measurements.
AB - Purpose. To determine the optimal geometry for keratoprostheses. Methods. A number of biopolymers were considered, among them, various plastics such as pMMA or pHEMA and various polysiloxanes. Their refractive index and dispersion were measured using an Abbe refractometer (Zeiss, Germany) and the values were incorporated in the framework of an eye model derived from the Gullstrand's eye model. Ray-tracing methods were used to determine the optimal parameters of the keratoprosthesis as a function of the eye parameters. The field of view was then calculated using paraxial approximations. Results. Flat designs, i.e. designs where the length of the keratoprosthesis is smaller than its diameter, are advisable because the field of view is enlarged and decentration problems are minimized. If the material used has a low refractive index, optical aberrations should be corrected with aspherical surfaces. Conclusions. New flexible biopolymers with a low refractive index such as polytrifluorosiloxane, are potential candidates for keratoprosthesis. They are mimicking the actual cornea, allowing a design as close as possible to the physiological conditions, while their flexibility may enable IOP measurements.
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M3 - Article
AN - SCOPUS:33750159425
VL - 37
JO - Investigative Ophthalmology and Visual Science
JF - Investigative Ophthalmology and Visual Science
SN - 0146-0404
IS - 3
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